src/mediapills/dependency_injection/__init__.py
# Copyright (c) 2021-2021 Mediapills Dependency Injection Authors.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
import inspect
import types
import typing as t
from functools import update_wrapper
from functools import wraps
from mediapills.dependency_injection.exceptions import ExpectedCallableException
from mediapills.dependency_injection.exceptions import FrozenServiceException
from mediapills.dependency_injection.exceptions import RecursionInfiniteLoopError
from mediapills.dependency_injection.exceptions import UnknownIdentifierException
__all__ = ["Container"]
Callable = t.Callable[..., t.Any]
Dict = t.Dict[t.Any, t.Any]
"""Callable value with lazy load implementation."""
SERVICE_MODE_COMMON = 2 ** 0
"""Callable value without lazy load implementation."""
SERVICE_MODE_FACTORY = 2 ** 1
"""Extended callable value."""
SERVICE_MODE_EXTENDED = 2 ** 2
"""Prevent callable from being modified."""
SERVICE_MODE_FINAL = 2 ** 3
"""Callable value with enabled autowiring."""
SERVICE_MODE_KEYWORDED = 2 ** 4
"""Available service types"""
SERVICE_MODES = frozenset(
[
SERVICE_MODE_COMMON,
SERVICE_MODE_FACTORY,
SERVICE_MODE_EXTENDED,
SERVICE_MODE_FINAL,
SERVICE_MODE_KEYWORDED,
]
)
# class ServiceMode(Enum):
# COMMON = SERVICE_MODE_COMMON
# FACTORY = SERVICE_MODE_FACTORY
# EXTENDED = SERVICE_MODE_EXTENDED
# FINAL = SERVICE_MODE_FINAL
# KEYWORDED = SERVICE_MODE_KEYWORDED
def handle_unknown_identifier(func: Callable) -> t.Any:
@wraps(func)
def wrapped(*args: t.List[t.Any], **kwargs: t.Dict[t.Any, t.Any]) -> t.Any:
self, key = args
if key not in self:
raise UnknownIdentifierException(key)
return func(*args, **kwargs)
return wrapped
class Container(dict): # type: ignore
"""Container DI implementation."""
def __init__(self, *args, **kw) -> None: # type: ignore
"""Create a new object."""
super().__init__(*args, **kw)
self._raw: t.Dict[str, t.Any] = dict()
self._protected: t.Set[t.Any] = set()
self._frozen: t.Set[t.Any] = set()
self._templates: t.Set[t.Any] = set()
def _freeze(self) -> None:
"""Warm up all offsets."""
for k in self:
if k not in self._frozen:
self.__getitem__(k)
@handle_unknown_identifier
def __getitem__(self, key: t.Any) -> t.Any:
"""Return the value at specified offset."""
# TODO: add __dependency_injection_result__ attr
if key in self._protected:
return dict.__getitem__(self, key)(self)
raw = dict.__getitem__(self, key)
if key in self._raw or not hasattr(raw, "__call__") or inspect.isclass(raw):
return raw
dict.__setitem__(
self,
key,
lambda di, k=key: (_ for _ in ()).throw(RecursionInfiniteLoopError(k)),
)
result = raw(self)
dict.__setitem__(self, key, result)
self._raw[key] = raw
self._frozen.add(key)
return result
def __setitem__(self, key: t.Any, val: t.Any) -> None:
"""Assign a value to the specified offset."""
if key in self._frozen:
raise FrozenServiceException(key)
if callable(val) and not hasattr(val, "__dependency_injection_mode__"):
val.__dependency_injection_mode__ = SERVICE_MODE_COMMON
dict.__setitem__(self, key, val)
def __delitem__(self, key: t.Any) -> None:
"""Unset an offset."""
# TODO: implement for factories
self._protected.discard(key)
self._frozen.discard(key)
self._raw.pop(key, None)
dict.__delitem__(self, key)
def clear(self) -> None:
"""Remove all offsets."""
# TODO: implement for factories
self._protected.clear()
self._frozen.clear()
self._raw.clear()
dict.clear(self)
def values(self) -> t.Any:
"""Return a new view of the dictionary’s values."""
self._freeze()
return dict.values(self)
def items(self) -> t.Any:
"""Return a new view of the dictionary’s items."""
self._freeze()
return dict.items(self)
def copy(self) -> t.Any:
"""Return a shallow copy of the dictionary."""
self._freeze()
return dict.copy(self)
def update(self, others: t.Union[dict, t.MutableMapping]) -> None: # type: ignore
"""Update the dictionary with the key/value pairs from other,
overwriting existing keys.
"""
for key, value in others.items():
self.__setitem__(key, value)
return dict.update(self)
@handle_unknown_identifier
def raw(self, key: t.Any) -> t.Any:
"""Get a parameter or the closure defining an object."""
if key in self._raw:
return self._raw[key]
return dict.__getitem__(self, key)
def template(self, key: str, template: str) -> None:
"""Format the specified value(s) and insert them inside the string's
placeholder.
"""
self.__setitem__(key, template)
self._templates.add(key)
@staticmethod
def _cp_func(func: t.Any) -> t.Any:
"""Make deepcopy of a function.
Based on http://stackoverflow.com/a/6528148/190597 (Glenn Maynard)
"""
copy = types.FunctionType(
func.__code__,
func.__globals__,
name=func.__name__,
argdefs=func.__defaults__,
closure=func.__closure__,
)
copy.__kwdefaults__ = func.__kwdefaults__
return update_wrapper(copy, func)
def service( # dead: disable
self, key: str, mode: int = SERVICE_MODE_COMMON
) -> Callable:
"""Assign a callable value to the specified offset."""
def decorator(func: Callable) -> t.Any:
if not callable(func):
raise ExpectedCallableException()
if mode > sum(SERVICE_MODES):
raise ValueError(mode)
if mode & SERVICE_MODE_EXTENDED and key not in self:
raise UnknownIdentifierException(key)
val = self._cp_func(func=func)
val.__dependency_injection_mode__ = mode
if mode & SERVICE_MODE_EXTENDED:
val.__dependency_injection_callable_base__ = self.get(key, None)
if mode & SERVICE_MODE_KEYWORDED:
val.__dependency_injection_callable_args__ = val.__code__.co_varnames
self.__setitem__(key=key, val=val) # type: ignore
return func
return decorator
# def factory(self, key: str) -> Callable:e
# """Mark a callable as being a factory service."""
#
# def decorator(func: Callable) -> t.Any:
# func = self._wraps(key=key, func=func, mode=ServiceMode.FACTORY)
#
# raise NotImplementedError()
#
# return decorator
#
# def extend(self, key: str) -> Callable:
# """Extend an object definition."""
#
# def decorator(func: Callable) -> t.Any:
# func = self._wraps(key=key, func=func, mode=ServiceMode.EXTENDED)
#
# # TODO: save extension chain
# raise NotImplementedError()
#
# return decorator
#
# def keyworded(self, key: str) -> Callable:
# """Mark a callable arguments as named auto full filled."""
#
# def decorator(func: Callable) -> t.Any:
# func = self._wraps(key=key, func=func, mode=ServiceMode.KEYWORDED)
#
# raise NotImplementedError()
#
# return decorator
# def protect(self, key: t.Any) -> None:
# """Protects a callable from being interpreted as a service."""
#
# if key not in self:
# raise UnknownIdentifierException(key)
#
# self._protected.add(key)
#
# def extend(self, key: t.Any, callable: Callable) -> None:
# """Extends an object definition."""
# if key not in self:
# raise UnknownIdentifierException(key)
#
# if key in self._frozen:
# raise FrozenServiceException(key)
#
# if key in self._protected:
# raise ProtectedServiceException(key)
#
# raw = self.raw(key)
#
# if not hasattr(raw, "__call__"):
# raise ExpectedInvokableException(key)
#
# extended = lambda di, func=callable, base=raw: func(base(di), di) # noqa: E731
#
# self._factories[key] = extended
#
# self.__setitem__(key, extended)